Are u good in your A to Z

Boy:- Are u good in your A to Z?

Girl:- Yea!

Boy:- Look at these

"ABCDEFGHIJKLMNOPQRSTVWXYZ"

Which letter is missing?

Girl:- Hmmmm.."U"?

Boy:- Yeah, where did that letter go?

Girl:- I dont know, where ?

Boy:- "U" went inside My Heart !